The invention relates to a method for the manufacture of a toothed gear device for the manufacture of a toothed gear and a tool for deburring the front-end edges of the inter-teeth grooves of a gear.
It is known to produce toothed gears by means of so-called hobbing cutters. Hobbing cutters have a worm as a geometrical body to start from. When the worm is given clamping grooves hobbed teeth are obtained which, when subjected to relieving, become then able to cut. After gear-like workpieces are hobbed the front-end edges of the inter-teeth grooves and tooth heads will have sharp edges, specifically at the side at which the hobbing tool exits. It is known to remove the burr in a manual operation. Further, it is known to remove the burr by grinding, profile milling or by means of press rolling.
DE 199 02 035 has made known a method for the removal of burr from the front-end edges of the inter-teeth grooves on gear-like workpieces in which the tool's axis of rotation is operated at a fixed radial spacing from the workpiece's axis of rotation and at a fixed axial spacing from the tool's front-end face at a constant speed ratio with respect to the workpiece which is continuously driven by rotation, a cutter plate seated on the tool axis forming cutting edges for chamfering the groove root edge at a predetermined root chamfering angle, chamfering a first groove flank edge at a predetermined flank chamfering angle, and chamfering a second groove flank edge opposed to the first one at a predetermined flank chamfering angle. At this point, chamfering is not continuous, but is discontinuous in a single-piece procedure.
All known devices have in common that they are machined on a device which is separated from the hobbing machine. Normally, the manufacturing process of a toothed gear is such that a blank is first turned on a lathe and finally is machined by a hobbing cutter on a machine tool. After hobbing, deburring is done in a separate device and is then followed by shaving as a micro-machining operation which can be performed again on the same machine tool on which the hobbing procedure is carried out.
The methods which are known exhibit considerable disadvantages. A separate deburring device will naturally increase the need for machining equipment. Expenditure in manufacture arises by the need to transfer the rough-hobbed gear to the deburring device, which requires a certain time for transport and retooling. A further drawback of the known method is that it has a relatively large cycle time.
It is the object of the invention to indicate a method for the manufacture of a toothed gear from a gear blank in which the removal of burr involves a distinctly lower expenditure in manufacture and machining equipment.